1. Field of the Invention
The subject application relates to a mobile device and particularly relates to a mobile device using a metal frame partially formed on a periphery thereof to form a loop antenna.
2. Description of Related Art
As mobile devices rapidly develop, the manufacturers not only need to improve the functions of their products but also need to make their products unique, so as to satisfy the demands from the market. For example, now mobile devices are mostly designed with appearances of metallic texture for emphasizing the uniqueness. However, the appearance design of metallic texture usually requires combining a conductive structure into the mobile device, which may affect signal reception of the mobile device.
In view of this problem, some improvements have been proposed, e.g. U.S. Pat. No. 8,009,110, US 2011/0133995, and US 2011/0241949. Specifically, U.S. Pat. No. 8,009,110 discloses forming a notch on a frame of a housing, and the notch are used to form two ground terminals and a feeding terminal. Accordingly, the frame of the housing forms a loop antenna for the mobile device to receive and transmit radio frequency signals. However, the formation of the notch changes the original structure of the frame and impairs the beautiful streamline appearance of the mobile device.
Moreover, US 2011/0133995 discloses cutting a frame of a housing with a gap and using a part of the frame to form a loop antenna. According to US 2011/0241949, a frame of a housing is also cut with a gap, and a part of the frame is used to form an inverted F antenna (PIFA). However, in the aforementioned disclosures, the formation of the gap damages the original structure of the frame, and the mobile device needs to have a sufficient clearance area at the bottom for forming the loop antenna or the inverted F antenna.